The Premier mandatory event in the Californian desert is one of the biggest tournaments outside of the grand slams but neither of the Williams sisters have played there since 2001, when they were subjected to heckling and, allegedly, racist abuse.
The crowd turned against the Americans after Venus pulled out of a scheduled semi-final clash with Serena, who was then booed during the final against Kim Clijsters.
They have resisted all calls to put the past behind them, but Serena revealed last week she had considered the issue after watching the Nelson Mandela biopic Long Walk To Freedom.
She said: "It actually crossed my mind a couple of days ago, after I saw the movie. I thought about it."
Tournament director Steve Simon is not taking anything for granted but he is hoping Serena will end her 13-year absence.
Simon said on bnpparibasopen.com: "While it is too soon to know whether she will play or not, we are pleased to see Serena's name on the entry list.
"Based on her comments at the Australian Open, we know playing in the tournament is something she is thinking about."
Venus' name is conspicuously absent, though, so it appears the sisters may be divided about a possible return.